Vector-borne diseases are still a major mortality factor in Africa and South-east Asia and effective mosquito repellents are therefore needed. DEET, chemically known as N,N-Diethyl-meta-toluamide, of DEET, is a slightly yellow oil, which is commonly used active ingredient in insect repellents to prevent bites from insects such as mosquitoes, biting flies, fleas and small flying insects.

DEET was first developed by the United States Army during World War II as early as 1946. DEET is applied to the skin or to clothing in different dosage forms to provide protection against tick bites, mosquito bites, and other insects that can transmit diseases.
DEET is regularly sold and used as spray or lotion in concentrations up to 100%. Consumer Reports found a direct correlation between DEET concentration and hours of protection that gives against insect bites. It was found that a 100% DEET offers up to 12 hours of protection while lower concentrations of 20%-40% offers 3 to 8 hours of protection. The Center for Disease Control recommends 30-50% concentration of DEET to prevent the spread of pathogens carried by insects.
N,N-Diethyl-m-toluamide (DEET) is one of the most effective and commonly used mosquito repellents. However, there are recent reports about the insect resistance to DEET, particularly, mosquitoes. Therefore, the search for new insect repellents is an important area of research to fight against the threat posed by increased number of infections indirectly caused by various insects. The synthesis of novel insect repellents is in demand, as insects are developing resistance to commonly used insect repellents such as DEET. Since, DEET is not reported to have any adverse health issues in animal; the research is progressing in search of novel analogs of DEET which are more or equally effective as DEET while addressing the issue of DEET resistance. There are few reports on novel analogs of DEET as insect repellents. One such report in an article titled “Biting deterrent activity of a DEET analog, two DEPA analogs, and SS220 applied topically to human volunteers compared with DEET against three species of blood-feeding flies” published in J Med, Entomol. 2006 November; 43(6):1248-51, discloses that two DEPA analogs, N,N-diethyl(3-bromophenyl) acetamide and N,N-diethyl[(alpha,alpha,alpha-trifluoro-m-tolyl)]acetamide, and one DEET analog, N,N,diethyl[3-(trifluoromethyl)]benzamide, had biting-deterrent activities that were superior to DEET against Aedesaegypti (L.) and Anopheles stephensi Liston.
Further insect repellent activity of Si-substituted amino methyl silane is reported in Pharmaceutical Chemistry Journal October 1974, volume 8, issue 10, pp 611-613 by É. Lukevits et al. Article titled “Biological Activity of Nitrogen-Containing Organosilicon Compounds” by E. Lukevics in Nobel Foundation Symposia Volume 40, 1978, pp 435-445 discloses organosilicon derivatives of amino-alcohols having insect-repellent and anti-microbial properties. Bhattacharjee A K et al. in Am J Trop Med Hyg. 1999 January; 60 (1): 1-6 discloses specific molecular electronic properties of N,N-diethyl-m-toluamide (DEET) analogs and their insect repellent efficacy.
In view of the foregoing, there is definite need in the art to provide effective insect repellants to address the public health issues.